Construction of spring buffers



F NI BL0cK-. CONSTRUCTION 0FY SPRING BLIFFEBS.

APPLICATION FILED` .IAN.I0I |922.

oo 6 -I f, 1,/ IIIMWV Q Il IL If 7 E Vj am 8 1 9 IV I, III I I f I I IIII IIII a 7% w Zw @I Z u ad UNITED STATS FREDERICK NIBLOCK, or SINGAPORE, srnarrs snrrnnmnnrs.; p'

. l Vconsrnucirroiv or SPRINGpistrfrrnns.'v

Application'sied January 1o, 1922.' serial No. 528,133. a

providea typev of spring buffer which shall` be better` able to resist fracture of the spring when under load than the" buffers now in general use comprising a cylindricalor helical spring of square or other section. I

vAccording to this invention,"the spring buffer comprises a spring of the conical type and means whereby the movement of `each larger and weaker coil of the spring when' under load is successively arrested lbefore such coil reaches a conditio'nof undue ldistortion. With this object a spring is used inV the buffer, `the winding `of which is of the 'usual conical type, that is to say the spring is of some sectionwire the coils ofgwhich vary in diameter from one end to the other. If desired also `the coilsl vmay'increase in pitch from one end lof the-spring to the other as well as vary in diameter and thus be a combination y ofthe conical and volute types ofA spring. In a conical and volute form of spring the larger diameter coils move most when under compression. VThis is taken advantage of in the present invention. The conical spring is formed upon a mandrel preferably of such shape that when the spring Wire is wound thereon the coils lie closely against each other, but, if desired, the mandrel may be so shaped that the coils of the spring are at some' pitch apart. v

The spring after being formed onthis mandrel is then extended to the final pitch required, which will always be greater than that of the mandrel upon which it hasj been formed, and the spring is then tempered.

Consequently the spring so formed when pressed` close would Vlitthe mandrelor a similar sized and shaped element. A secondv support element is now made somewhat like the mandrel but With a pitch greater than that of the original mandrel, and Vis positioned in theV larger. diameter end of the spring which latter and the support are housed Vin any usual type of buffer frame.

The mandrel upon which the spring is pri.

marily formed may be a stepped mandrelV or it may be trulyconical, the support element vllspeciication of Letters Ilatent.:A :Patentedv Apr. 4,1922.

orV conical. Y' 1 l Y 'The invention is'illustrated 1n the'accombeing similarly shaped,`that is, either stepped ich. l M Y',

pauying drawings in which Fig'.` ll, is an`ele. .Y

vationI of a buffer with the spring in section f andthe support element in position,Fig. 2',Vv beingan elevation of a `mandrel suitableforformingthe spring shown in Fig. 11.' In carrying out the invention, a mandrelj'll` is provided uponr the spiral steps' Sion",v whichy the spring wire 2 of some suitable section,

such as the square form lshown,is wound.

With the formA of mandrel shownV ingFigfQ,

the coils of the springwould lie-,closely one againstthe other.,the pitcherl of the steps'beingV equal tol thefdepth A-of thewire sec-` tion. After beingf'formed-.on themandrel,`

thesp'rin is taken off and opened out 'toI theY desired pitch andfis then positioned in any usual type ofbuifer frame comp'rising,say, upper and r lower yokes- 4, "5, adapted tov be'- Ldrawn together to compress-thel springV by i outerrods 6 and a central rod 7, each of the y three rods having.V an eye' 8 and a retaining nut 9.. A support elementl l() is insertedin sol the buffer frame and inside the larger diamter end of the spring 2,-thi's support being I formed with spiral steps or shoulders after. the manner of vthe mandrel 1 butwith the longitudinal pitch b of its steps greater than the corresponding pitch a of the mandrel but less than the pitch to whichthe spring Y coils have been opened.L Consequently the larger diameter or lowercoils of the spring 2, when in the uncompressed position roun the support l0, will all be free of' the steps., 10al of the support. A e f When the spring is under lcompression the largest diameter end coil 2a of the springr 2 will, owingto its greater movement,iiirstbed and come to restV on the largestjdiameter step 10a of the supportlO, andsuch Ycoil 231 Vwill come to restV ina distortion condition of y its wire lying between its full eirtensio'n or free condition and its'closed up limit corresponding to the initialdisposition of the coils when being /wound close togetheron kthe Y mandrel. The lowest c oil 2a of the spring i will therefore bedon the corresponding step orA shoulder of the'mandrel beforeV fracture f of the spring wire in that vcoil is at vall'lilrely l to occur. vAfter the largest coilhas'beddedy in the manner described, the resistance-of largestcoil which will offer greater resistance than the previous coil now bedded but less than the succeeding free coils. This sec-l out of action before reaching its elastic limit,

instead of the Weakest'coil beingliable to be unduly strained as in the usual conical type otspring. c Y

The mandrel upon which the spring steel is Wound When hot, may be made ot', say, only halt' the pitch of the support which is inserted inthe buffer, and this support may be a sheet metal stamping or other abutment against which the thrust oi thespring is taken. f y

Though the mandrel l and supportQ have been particularly described as Vo1 spiral stepped or shouldered construction, the mandrelmay take the form of aV conical element, the support which is afterwards inserted in the coil being also a conical element but less acute than the mandrel, the sequential bedding of successivercoils taking place on the more obtuse conical support element in the samel Way as that described with reference to the stepped element.

I claim. Y l'. A spring buffer, comprising, a coiled spring, a stepped support c'o-operating With bed, the pitch ot. the steps of the support being less than that of the coils .in the spring when uncompressed.'

3. A spring butter, comprising, a spring the coils of which are Wound in conical 'formation, aspirally stepped support co-operat-A ing with the larger coils of the spring so'that such coils may bed thereon, as Vthe spring is compressed, the pitch of the steps ofthe support being less than thatof the coils inthe spring when uncompressed.Y

47.' Ai spring buffer, comprising, a spring the coils of which are Wound in conical Vtorination, a buffer frame Within which the spring is housed, a spirallystepped support element housed Within' the spring, the .steps of thesupport being adapted to arrest the movement of the ,spring coils when .the spring is compressed, and the pitch kof the steps of the support being-less than that otV the coils inthe spring When uncompressed.V

In testimony whereofV I atti-2;'V my signature in presence of two Witnesses. w

lVitnessesi l f A, J. DAX/ins, y E. HIGINBOTHAM. l

l FiniDanieli NiBLooK. 

